Paul Eggert wrote:
I also found some saying that the transition was 02:00->01:00:
https://vanguardia.com.mx/articulo/todo-lo-que-debes-saber-sobre-el-cambio-d... ... so it appears at the least that there is some confusion here.
To make things even more confusing, an October 2017 article in Vanguardia said the opposite, i.e., that the 2017 transition was 03:00->02:00: https://vanguardia.com.mx/articulo/lo-que-debes-hacer-para-que-el-cambio-de-... So did Vanguardia correct the time this year? or were they correct last year? I suspect that most people in Mexico who set the time by hand, did this the night before (or the morning after). Places like hospitals and airports care more about this sort of thing. I looked for when airports changed, and found announcements like this one: https://www.publimetro.com.mx/mx/noticias/2018/10/22/aeropuerto-capitalino-a... which said that AICM (the main airport in Mexico City) "atrasará una hora todos los relojes en sus pantallas de información de vuelos, el próximo domingo 28 de octubre en punto de las 02:00 horas", which sounds like a 02:00->01:00 switch. Every airport announcement I found was similar. It is curious that so many news stories say there is a 03:00->02:00 transition, though.